Bark stripping machine



D 7, 1943- R, L. STEPHENS 2,336,375

BARK STRIPPING MACHINE Filed April 29, 1941 2 Sheets-Sheet 1 INVENTOR. Z a STEPHENS.

Dec.

R. STEPHENS BARK STRIPPING MACHINE Filed April 29, 1941 2 Sheets-Sheet 2 mh wm. Km, NN

Patented Dec. 7, 1943 UNITED .IzlTA'I'ES PATENT OFFICE 2,336,375 BARK STRIPPING MACHINE Robert L. Stephens, Downingtown, Pa.

Application April 29, 1941, Serial No. 390,870

v 4 Claims.

The present invention has to do with bark stripping machines, and is concerned primarily with the provision of a machine that operates on principles novel to this art.

The invention has in view as its foremost objective the provision of a bark stripping machine which essentially comprises three mechanisms. One of these is mechanism for rotating a log substantially about its center. Another is a cutter assembly, and the third is traveller mechanism for causing the cutter assembly to travel along a log coincident with rotation thereof.

An important object of the invention is the provision of a cutter assembly that includes a cutter which operates in a novel relation with respect to the log. In accordance with this invention, the cutter is intended to rotate at a comparatively high speed on an axis that substantially intersects the axis of the log, the bark of which is being stripped.

Another object of the invention is to provide in a bark stripping machine of the character above-noted, a cutter assembly which includes a cutter element that is spring actuated so as to provide a yielding feed on the part of the cutter.

Still more in detail the invention has as an object the provision of a cutter assembly including a cutter together with a guard that is adjustable with respect thereto. Thi guard has an outer convex face which is designed to engage irregularities on the bark of the log with a cam action to cause a retraction of the cutter in such manner as to accommodate the irregularities.

A further object of the invention is the provision of a cutter assembly of the character above-noted which includes guide arms that are mounted to embrace a log, the bark of which is being stripped, therebetween. These guide arms are pivotally mounted and spring actuated to normally urge the extremities thereof against substantially diametrically opposite points of a log.

An important feature of the invention is the provision of mechanism for causing a retraction of the cutter and guard coincident with expansion of the guide arms.

Another object of the invention is the provision of a bark stripping machine of the character above-noted which includes a cutter assembly that is pivotally mounted on the traveller mechanism so as to swivel with respect thereto.

Various other more detailed objects and advantages of the invention are tied up with the provision of a cutter assembly which will function in accordance with the above-noted objects. These will in part become apparent and in part be hereinafter stated as the description of the invention proceeds.

The invention, therefore, comprises a bark stripping machine consisting of log rotating mechanism, a cutter assembly including a spring actuated rotary cutter that rotates on an axis that substantially intersects the axis of the log carried by the rotating mechanism, and traveller mechanism for causing th cutter assembly to move along the log coincident with rotation thereof.

For a full and more complete understanding of the invention, reference may be had to the following description and accompanying drawings wherein:

Figure l is an end view of the essential parts of a bark stripping machine which is made in accordance with the precepts of this invention,

Figure 2 is a top plan view of the cutter assembly per se,

Figure 3 is a detailed view in perspective of the cutter element,

. Figure 4 is a detail section through the guard for the cutter, and.

Figure 5 is a view in ide elevation of the cutter assembly per se.

Referring now to the drawings, wherein like reference characters denote corresponding parts, and first more particularly to Figure 1, the bark stripping machine of this invention is shown as comprising a cutter assembly referred to in its entirety by the reference character C, log rotating mechanism identified at R, and traveller mechanism designated T. p

The supporting structure for the various mechanisms is not herein described in detail, as it is not believed to be an essential part of the invention. It suffices to say that a pair of brackets It and It are spaced vertically an appropriate distance apart and included as part of the supporting structure illustrated.

Depending from the top bracket II is a hub structure designated l3, and mounted in this hub structure I3 is a screw pin l4 having a pointed end l5 that is designed to be embedded in a log substantially at the center thereof. The screw pin I4 is provided with appropriate operating means such as a handwheel illustrated at I6. The log is designated L and when mounted in the mechanism R, the handle it will be rotated to force the point l5 into the center of this log L.

Carried by the bottom bracket It], substantially opposite to the hub structure Hi, there is another similar hub structure ll which rotatably carries a shaft It. At the lower end the shaft I 8 has keyed thereon a gear 19 while on the upper end the shaft drivably carries a head 20 from which projects a plurality of spikes 2|. As the handwheel I6 is rotated, not only the point I5 is embedded in the log L, but the log L is also forced against the spikes 21. Thus, a driving relation between the shaft 18 and log L is set up by spikes 2 l.

Any appropriate source of power for drivingtheshaft l8 may be availed of. A simple arrangement may be employed, such as an electric motor designated 22 having a drive shaft 23 which car'- ries a pinion 24 that meshes with gear IS.

The traveller mechanism T is positioned for movement between the top and bottom brackets l and H. As illustrated in Figure 1, a slide bar 25 extends between these brackets l0 and Hand has its ends securely anchored thereto.- The slide bar 25 is preferably circular in cross-section whereby its cross-section is rendered complemental to the bore 26 of a tubular guide member 2'5 which iscformed a a part of a cutter assembly support 9.

A screw member 28 has its extremities journaled in bearing members 29 and 38 carried by the brackets in and l l, respectively, and this screw member 28- is threaded through a threaded bore 3| formed in a sleeve 32 which is carried by the cutter assembly support 9. The lower end of the screw stem 28 adjacent the electric motor 22 has keyed thereon a pinion 33 which meshes with a gear 34 that in turnmeshes with gear it.

It is evident that when the electric motor 22 is operated, the log L is rotated at the same time the screw stem 28 is rotated to cause a traveling of the support 9 and cutter assembly C along the slide bar- 25.

Referring now more particularly to Figures 2 and 5, the cutter assembly C is shown as comprising a casing 35. Housed in this casing 35 is an electric motor 36 which has a drive shaft. that projects from one end thereof and which drive shaft carries on its projecting end a pulley: 3?.

The casing 35 carries a bottom plate 8 (Figures 1 and which is spaced from and beneath the motor 38. This plate 8 is formed with a pivot opening. A slide bracket 1 has offset side flanges S'that rest on the cutter assembly support 9. This bracket 1 is formed with'a pivot opening in alignment with the opening in plate 3. pin 5 passes through these aligned openings.

Retaining members 4 may be secured to the support 9 in any preferredmanner,.as by screw' fastening elements 3. These members 4 carry flanges 2 that overlie and engage the flangesfi to hold the slide bracket 1 in position on the support 9.

It isevident that the structure described in the two preceding paragraphs permits of the ready assembly or disassembly of the cutter. assemblyiC from the traveller mechanism T. At thesame time a swivel relation between these parts is es.-'

tablished.

A lug 80 depends from theslide-bracket l and this lug 86 is formed with a threaded opening;

Another lug 8i upstands from the support 9; This lug 81 has a threaded openingin alignment with the opening in the lug 8G. Ascrew stem 82T is screwed into these aligned openings and: carries an operating member in the formpi a-hand-- wheel 83. 82 causes adjustment of the cutter assembly?- C relative to support 9 oflthetraveller mechanism;

Mounted on the casing 35 at'the-top is a tubu'-- A- pivot Obviously, rotation of this screw stem.

lar member 38 having one end passing through an opening 39 formed in an end plate 40. The other end of the tubular member 38 is closed by a collar 4| formed with a central opening through which passes a tubular shaft 42. This shaft 42 extends entirely through the member 38 and projects an appreciable distance in front of the end plate 40.

At one end this tubular shaft 42 is formed with aslot 43' which functions. as a keyway. Keyed to this shaft 42, through the medium of the keyway 43, is a pulley 44 and a belt 45 (see Figure 5) drivably connects the pulley 44 with the pulley 31. The shaft 42 is preferably journaled in a bearing member 46 which is carried at the end of the member 38 adjacent the end plate 401 As shown in Figure 2, this bearing member 46 has a ring-like extension 41 which is bolted tothe end plate 40 and the electric motor 36 by screw bolts 48 which also hold in position a1guard 49for the pulley 44,

The". shaft 42 carries,. at an appropriate point within the member 38,la collar 50 which may be adjustably mounted thereon through the medium ofv a set screw 51'. An expansion spring 52 is interposed between this collar 50 and the collar 4|; The tendency of this expansion spring 52 is to urgetheslotted end of the shaft 42 toward thelog L, thatlis, to the right, speaking with reference to the showing of Figure 2.

Acutter element is. shown in detail in Figure 3 and includes a stub shaft 53 that is.received in theouter end'of the shaft 42 and keyed thereto to establish a drivingv relation. The outer end of thisimembers 53 carries cutting teeth 54, each of which is formed with a point at 55 that is designed to bite into the bark of the log L. An expansion coil'spring 56 is shown as interposed between one end of the stub shaft 53- and anabutment 5'! within the tubular shaft 42; Thus, the cutter element itself is spring-backed by the springi56;

A guard for the cutterrelement issshown in detail in Figured and designatedjfl; This guard comprises a ring-like member: having an outer convex surface A sleeve 59 merges inwith the convex surface'at the centerrof the ring, ,and i this sleeve'59 is'adapted to fit about the teeth 54 of the'cutter'. Are'duced'sleeve extension 60 snug-- 1y; engages the: shaft 42;.and a set screw 6| may be availedofas a means'for holding: the guard.

inan: adjusted position withrelation to the shaft 42 andithe teeth of the cutter'element. Itisiobvious that: this adjustment between the guard and the teeth 54 of the; cutter element determines the' thickness ofthe out which is made asthe machine operates.

Pivotally mounted.on the end' plate 40 are a pair ofiguicle'arms 62' and 63;v The guide'arms 62' and 63: have outer: ends that are relatively flared and: which are adapted to engage the: log; L, as shown-.in Figures 1 and2. The flared extremities of'the'arms are designated 64; Each of the'guide'a'rms 6'2" and: 63 consists of a bell crank structure that is pivotally mounted'at 65 to a lug 66' that. projects forwardly of. the end plate;

Each of the bell cranks. also includes a short arm 67' and: aitensionspring 68' has one'end con-- nected to an end of the. short arm' 6'! while its other end is "anchored 'to the'endplat'e 40; These springs'B-S exert a tendency-tov cause'the flared ends: 64 of the guide arms "62' and t3 to move. inwardly'towards-onelanothe1n Anoperating member is'sliown at 69'. andlis pivotally mounted at on a supporting bracket H that is carried by the tubular member 38. The inner end of the shaft 42 carries an enlargement '12 that is engaged by a curved extension 73 carried by the handle member 69. This extension 13 may be cut away to accommodate the shaft 42, the cutaway being shown at 14. A link 15 has one end pivotally connected to the handle member 61, as shown at '16, while the other end of the link 15 is connected to wire connections H as shown at 18 and each of these wire connections 11 is in turn connected to the outer end of a short arm 79 that is a part of the bell crank arms 62 and 63 that extends in a direction opposite to the short arms 61. Thus, when a pull is exerted on the link 15, the outer extremities of the arms 19 are moved inwardly to cause an outer movement of the extremities of the arms 61 against the influence of the spring 68. This causes a spreading of the flared end 64 of the uide arms 62 and 63.

While the mode of operation of the above-described bark stripping machine is believed to be obvious, it may be briefly described by noting that the log L which is to be stripped is first placed in a vertical position in the mechanism R and forced onto the pinions 2| by the handwheel l6, which operation also causes the point l5 to become embedded in the log L. The cutter assembly C is now moved to the upper end of the log.

The operating member 69 is now operated and rotated in a counterclockwise direction, speaking with reference to the showing of Figure 2. This causes two things: it causes the flared ends 64 to spread and, at the same time, the shaft 42 is moved to the left against the action of the spring 52. This causes a retraction of the cutter element and the guard associated therewith. When the operating member 69 is released, the spring 52 causes the cutter element to engage the log L, while the springs 68 cause the flared ends 64 of the guide arms 62 and 63 to embrace the log L in the manner shown in Figure 2.

Both of the electric motors 22 and 36 are now started in operation. The operation of the motor 36 causes the shaft 42 to rotate rapidly and thus impart a corresponding rapid rotation to the teeth 34 of the cutter element. The motor 22 causes the log L to rotate, and, at the same time, the cutter assembly C is caused to travel along the slide bar by means of the screw stem 28. Thus, the bark is cut from the log along a line which determines a helix. After stripping, the log L may be released through the medium of the handwheel i6 and a new log positioned to have the bark stripped therefrom.

It is evident that the swivel relation between the cutter assembly C and the support 9 0f the traveller mechanism T, together with the guide arms 62 and 63, will cause the cutter to effectively follow a log regardless of the curvature thereof.

Thus, bark may be thoroughly stripped from loss of irregular or curved shape.

While a preferred specific embodiment of the invention is hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions illustrated and described since I wish to avail myself of all variations coming within the proper scope of the appended claims.

I claim:

1. A bark stripping machine of the character described comprising mechanism for rotating a log substantially about the axis thereof, a cutter assembly including a rotary cutter with the axis thereof substantially intersecting the axis of the log, means for rotating the cutter, and adjustable guard for varying the depth of the cut made by said rotary cutter, traveller mechanism for causing said cutter assembly to move along said log, means for automatically maintaining a substantially uniform depth of cut for logs having various shapes and sizes, said automatic means including a yielding feed for said cutter, and guide arms arranged on opposite sides of the axis of said cutter and embracing said log.

2. In a bark stripping machine including log rotating mechanism and traveller mechanism, a movable cutter assembly carried by said traveller mechanism and comprising a rotary cutter element, means for rotating said cutter element, and a convex guard disposed about said cutter element and being movable with respect thereto to vary the depth of cut of said rotary cutter element.

3. In a bark stripping machine, a cutter assemly including a rotary cutter, means for rotating the cutter, spring means backing said cutter and normally urging said cutter into engagement with the bark of a log, a pair of pivotally mounted guide arms disposed on opposite sides of said outter, spring means normally urging the free ends of said guide arms towards each other, and means for simultaneously retracting said cutter against the spring actuatin means and opening the extremities of said guide arms against the influence of the springs tending to close them.

4. A bark stripping machine comprising mechanism for rotating a log substantially about its axis, a slide bar, a cutter assembly slidably mounted on said slide bar, means for causing said cutter assembly to move along said slide bar coincident with rotation of a log, said cutter assembly including a rotary cutter mounted for rotation on an axis that substantially intersects the axis of said log, an adjustable guard for varying the depth of the cut made by said rotary cutter, means for yieldably urging said cutter toward the axis of said log, and guide arms on opposite sides of said cutter and embracing said log.

ROBERT L. STEPHENS. 

